Polishing and tumbling machines and barrels therefor



Sept. 1, 1964 E. 'E. SMITH 3,146,557

POLISHING AND TUMBLING MACHINES AND BARRELS THEREFOR Filed Feb. 4, 1963 21 2 3 f/vvE/v TOE.- 7 20" Eda/arm far/ 5112/17:

M5 HTTafM/Ey United States Patent 3,146,557 PDL'iSi-llNG AND TUMELING MACHINES AND BARRELS THEREFOR Edward Eari Smith, 411 W. Main St., New London, Iowa Filed Feb. 4, 1963, Ser. No. 255,743 4 Claims. (El. 51-164) My invention relates to tumbling and polishing apparatus for the finishing and polishing of minerals, gem stones and other irregular shaped articles, and more particularly to a novel construction of a rotating barrel or receptacle for performing such polishing and grinding action.

A number of forms of tumblers for the polishing of irregular articles, particularly minerals and stones, have been developed, all of which operate on the principle of rotating and tumbling such articles in a container along with an abrasive compound, the action of one stone or article on the other in the presence of such abrasive during the tumbling and rotating process serving to impart a high finish and polish to the articles. Many of these previous devices have not served to impart any motion to the load of stones other than pure rotation at slow speed, and have also been inefficient in that sharp interior corners of the tumbler barrel tend to cause the load of material to lodge and become fixed in such corners. Another disadvantage has been the use of metals or other materials which are eroded or worn by the action of the stones and abrasive compound contained therein which materially shortens the life of the tumbler barrel or container, and my invention has been designed and constructed to eliminate these objections as well as provide a much more ellicient tumbling and polishing machine and one which is economical to construct and operate.

In the preferred form of my invention, a tumbling barrel being substantially a polyhedron, having multiple sides or faces arranged in a definite sequence and manner is provided, which is angularly mounted on bearings, with respect to the horizontal, and rotated at a relatively slow constant speed by an electric motor and gear reducer or other suitable source of power. The polyhedral tumbler barrel itself is formed entirely in one piece of polyvinyl plastic by a moulding process and the interior thereof is completely free of square or acute angle interior corners, and has a highly polished, smooth internal surface characteristic of such plastic. The tumbler barrel is substantialy hexagonal in cross-section; however, it is not an equal hexagon as adjacent sides are flared oppositely, one side being narrow near the top or open end and wider at the base or shaft end, whereas the adjacent sides have surfaces that are oppositely flared and arranged and the net result of the unique arrangement of the sides of the polyhedron is to impart a back and forth or axial motion to the load of stones, minerals and abrasives as well as the normal tumbling motion imparted by rotation of the barrel. By virtue of the unequal hexagonal construction the central cavity of the barrel is eccentric to the axis, the eccentricity shifting each 60 degrees of rotation, and the load is shifted from one end of the tumbler or barrel to the other end six times each revolution or once every 60 degrees of rotation. This insures that the load is thoroughly mixed and thoroughly maintained in contact with the abrasive at all times.

Accordingly, it is an object of my invention to provide an improved tumbling and polishing machine for the finishing and polishing of gem stones, minerals and other objects of like size and nature.

It is another object of my invention to provide an improved tumbling and polishing machine which is simple, compact, easy to load, operate and unload, easily transportable, and which lends itself to economical manufacture and operation.

3,14%,557 Patented Sept. 1, 1964 A further object of my invention is to provide improved form of tumbling barrel for polishing machines which operates to thoroughly mix and agitate the load both in an axial plane along the axis of rotation as well as in a rotary plane.

Another object of my invention is to provide an improved tumbling and polishing barrel integrally formed and moulded of one unitary piece of plastic or other abrasive resistant material, and which eliminates any sharp or reentrant interior corners, thus insuring that the load is freely agitated and tumbled in all parts of the barrel and throughout the entire rotation cycle.

It is another object of my invention to provide an open end tumbling barrel of polyhedral form in which the sides are formed of trapezoidal panels arranged to provide an internal cavity of varying eccentricity relative to the axis of rotation.

My invention and the advantages contained therein will be better understood from the following description taken in connection with the accompanying drawings, and its scope will be pointed out in the appended claims.

In the drawings,

FIGURE 1 shows a perspective view of the tumbler and polishing machine forming the subject of my invention showing my novel and improved tumbling barrel in operating position.

FIGURE 2 is a top or plan view of the open or loading end of the tumbling barrel per se.

FIGURE 3 is a cross-section view through FIGURE 2 taken along the lines 3-3; and FIGURE 4 is another cross-sectional view of the barrel shown in FIGURE 2 taken along the lines t4-.

FIGURE 5 is a partial detail in cross-section showing the attachment of the driving shaft or spindle to the base of the moulded plastic barrel.

Referring now to the drawing, particularly FIGURE 1, my improved polishing tumbling apparatus comprises a base member it) and integrally cast or formed therein an upstanding pedestal 11, the upper portion of which is extended and formed as a handle grip 12 to permit the operator to easily pick up the device for transportation from one point to another. Also within the upper part of the pedestal ill, a bearing 13 extends through the pedestal 11 beneath the handle part 12, adapted to receive the rotating shaft 14 which is integrally secured to the base of the rotating tumbler or barrel indicated generally at 15. Also positioned upon the base 1d at the left end thereof is a motor and reduction gear unit housing 16 which may be of any convenient form or shape and is designed to house the drive motor (not shown) and necessary gear reduction unit for rotating the shaft 14 at the desired and appropriate tumbling speed, which is usually in the area of 1530 r.p.m., depending on the diameter of the barrel 15. Any form of desired coupling, shown at 17, may be utilized to interconnect the shaft 14 with the drive shaft from the motor 18, and while not shown, it is obvious that a flexible or other cushioned type of coupling can be used and many times is preferable for this appli cation. From the foregoing, it can be seen that the entire machine is of compact, unitary construction and preferably the base ltl, pedestal 11, and motor housing 16, may be integrally cast of light metal which can easily be handled and transported by means of the handle 12.

The tumbling and polishing barrel 15 is a polyhedron hexagonal in outline, as shown in FIGURE 2, and provided with an opening or aperture 19 at the outer end thereof for loading and unloading the gem stones, minerals or other objects to be treated.

From FIGURE 2 it will be noted that the polyhedral tumbler 15 consists of adjacent faces or sides which are dissimilar, for example, the three narrow sides or panels, 20, 2t) and 20", are alternately located between the three wider angled sides or panels 21, 21' and 21". About one-third of the way from the top of the barrel 15 the sides 20, 20 and 20", are respectively joined to a wide downwardly flaring panel, 22, 22 and 22" (as seen in FIG. 1). The sides alternately spaced between those last named are flared in the reverse direction, the wider portion thereof being at the outer or open end of the barrel l and these sides 23, 23' and 23 are, along with the lower or base edges of the sides 22, 22' and 22", integrally joined to the base 24 of the barrel 15. From FIGURE 1 and FIGURE 2 and the description in connection therewith it can be seen that the barrel is formed of an alternate series of trapezoidal surfaces, sides or panels, the parallel edges of these trapezoids all lying in a series of parallel planes perpendicular to the axis of rotation, and the angles formed by the non-parallel and the parallel sides of each alternate set of trapezoids are equal.

This unique construction imparts an eccentric interior cavity relative to the axis of rotation, of the barrel 15 which eccentric cavity shifts from one end to the other end axially every 60 degrees of rotation of the barrel. This can be seen by referring to FIGURES 3 and 4 which show cross-sections through the barrel at locations 60 degrees apart. For clarity, the barrel axis is shown as horizontal, however, in operation it would actually be positioned as shown in FIGURE 1, at an angle of 15 to 20 degrees from the horizontal. Thus, in FIGURE 3, the load would be lodged at the base end of the barrel 15 against the side 23' and after 60 degrees of rotation the barrel would be in the position as shown in FIGURE 4 where the load would be shifted outwardly away from the base and would rest against the outer end of side 22 and the bottom edge of side 26'. This shifting of the load will, of course, be repeated every 60 degrees of rotation of the barrel 15 which imparts a double action polishing and grinding of the load with the abrasive material included therein. The small flattened side panels 25 which are positioned between the pairs of sides 20, 2th, and 2t)", and 22, 22', 22" respectively, are merely for the purpose of avoiding a sharp, reentrant interior corner which might result in the load lodging or sticking in this position. The purpose of these small panels 25 can be seen in FIGURES 3 and 4.

Reference should now be had to FIGURE 5 which shows a preferred method of attaching the drive shaft 14 to the base 24, being a detail and cross-section through a portion of the base and shaft, and it will be noted that the shaft 14 is provided at its upper end with a fiat plate 26 which may be circular or hexagonal in shape and which is securely aflixed to, by welding or other means, the rotatable shaft 14 perpendicular to its axis. As mentioned earlier, the entire barrel 15 is moulded or cast in plastic in one mould and in one operation, and the assembled base plate 26 and shaft 14 are set in the mould prior to the moulding process in such position that the plastic completely surrounds the base plate 26, and the mould is recessed to provide for the thickened portion 27 on the underside of the base 24. This has been found to give an extremely secure mounting arrangement since the entire barrel itself is of light weight material and no difiiculties with fracture or breakage of the shaft 14 and its attached base plate 26, or separation of the base plate 26 and base 24 of the barrel 15 have been encountered. The lower end of the shaft 14 may be provided with any suitable notch or slot 28 as shown for engagement in the coupling 17, or as mentioned earlier, a flexible or shock absorbent coupling may be used at this point instead of the collar type coupling shown at 17.

It is believed that the operation of the improved form of tumbling barrel, together with its unique shape, being a polyhedron of trapezoidal panels, and its assembly on the unitary mounting base and power source, can be appreciated from the foregoing description and drawings. It is also desired to point out that the smooth interior surface of the barrel 15 has no ledges, corners or other undesirable features, lends itself to easy cleaning after use,

,4 and has also been found to no extremely resistant to the abrasive and eroding action of the load when agitated therein with suitable abrasive material. If desired, a hexagonal cover plate can be placed over the opening 19 during operation, although due to the fact that the barrel is set at a shaft angle of approximately 15 to 20 degrees to the horizontal when in use in the machine, this eliminates the need for such a cover unless an extremely heavy load to be polished is in place. The unique construction of this barrel provides a three dimensional tumbling action imparting both a rotational and an axial movement and combinations thereof, to the load while in operation, which materially reduces the tumbling and polishing time required as well as insuring better and more complete polishing action.

While there have been shown and described particular embodiments of this invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the invention and, therefore, it is intended in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A tumbling and polishing barrel comprising a polyhedral body including a planar polygonal base at one end, an opening of polygonal shape at the opposite end, said body being rotatable in use about an axis passing through the center of said base and the center of said opening, said body further including a plurality of side panels inter-connecting the base and said opposite end of the body, said side panels including a first group of angularly spaced trapezoidal panels projecting from adjacent said opening towards the base and outwardly relative to said axis, and a second group of trapezoidal panels corresponding in number and general arrangement to said first group of panels, said second group of panels projecting generally from said base with adjacent panels of said second group extending inwardly and outwardly respectively from the base relative to said axis.

2. A tumbling and polishing barrel comprising a polyhedral body including a planar hexagonal base at one end, an hexagonal opening in the end opposite to said base, and a plurality of trapezoidal side panels inter-connecting said base and the opposite end of said body including a first set of three equi-angularly spaced trapezoidal panels each having a first side edge positioned adjacent said opening and a second side edge parallell to said first side edge and positioned radially outwardly relative to said first side edge, a second set of three trapezoidal panels respectively positioned between said panels of said first set and each having a first side edge inter-connecting two of said first side edges of said first set of panels and a second side edge inter-connecting two of said second side edges of said first set of panels, said second side edges of said second set of panels having a greater length than said first side edges, a third set of three trapezoidal panels projecting radially outwardly from said base at equiangularly spaced locations corresponding to the locations of said first set of panels, and a fourth set of trapezoidal panels projecting radially inwardly generally from said base at locations between said third set of panels and corresponding to the locations of said second set of panels.

3. A tumbling and polishing barrel as defined in claim 2 further including a fifth set of three equi-angularly spaced trapezoidal panels inter-connecting corresponding pairs of panels of said first and third sets and extending at an obtuse angle relative to said corresponding pairs of panels.

4. A tumbling and polishing barrel as defined in claim 2 wherein said body has a one piece plastic construction and there is provided in combination a drive shaft having one end molded in said base of the body.

(References on following page) References Cited in the file of this patent 2,912,803 UNITED STATES PATENTS 2,924,914

550,781 Catlin Dec. 3, 1895 714,315 Lybrink Nov. 25, 1902 718,327 Brot'nwell Jan. 31, 1905 5 21,079

1,063,841 Stelter June 3, 1913 2,024,310 Sundback Dec. 17, 1935 641,237 2,721,426 Vincent 061. 25, 1955 787,479 2,899,181 Weydanz Aug. 11, 1959 877,422

6 Simjiam Nov. 17, 1959 Garwood Feb. 16, 1960 FOREIGN PATENTS Great Britain Sept. 3, 1914 France July 30, 1928 France July 8, 1935 Germany May 26, 1953 

1. A TUMBLING AND POLISHING BARREL COMPRISING A POLYHEDRAL BODY INCLUDING A PLANAR POLYGONAL BASE AT ONE END, AN OPENING OF POLYGONAL SHAPE AT THE OPPOSITE END, SAID BODY BEING ROTATABLE IN USE ABOUT AN AXIS PASSING THROUGH THE CENTER OF SAID BASE AND THE CENTER OF SAID OPENING, SAID BODY FURTHER INCLUDING A PLURALITY OF SIDE PANELS INTER-CONNECTING THE BASE AND SAID OPPOSITE END OF THE BODY, SAID SIDE PANELS INCLUDING A FIRST GROUP OF ANGULARLY SPACED TRAPEZOIDAL PANELS PROJECTING FROM ADJACENT SAID OPENING TOWARDS THE BASE AND OUTWARDLY RELATIVE TO SAID AXIS, AND A SECOND GROUP OF TRAPEZOIDAL PANELS CORRESPONDING IN NUMBER AND GENERAL ARRANGEMENT TO SAID FIRST GROUP OF PANELS, SAID SECOND GROUP OF PANELS PROJECTING GENERALLY FROM SAID BASE WITH ADJACENT PANELS OF SAID SECOND GROUP EXTENDING INWARDLY AND OUTWARDLY RESPECTIVELY FROM THE BASE, RELATIVE TO SAID AXIS. 